Early bird gets the lead poisoning: How pigeons are sentinels for our health

AUSTIN, Texas —That common grey bird eating out of the neighborhood garbage can may be an indicator of your own health.

A researcher at University of California Davis has discovered that pigeons living in New York City get lead-poisoned much as kids do.

“Pigeons live in the same areas, eat a lot of the same food, drink from the same water sources and are exposed to a lot of the same toxins that we are,” says Rebecca Calisi Rodríguez, an assistant professor in the department of neurobiology, physiology and behavior at University of California, Davis

With leaded paints and gasoline commonly used prior to the 1990s, heavy metals are widespread in the environment. In New York, where Rodríguez conducted her research, lead lingers in deteriorating paint, in dust accumulated on streets, and in polluted water and soil in densely trafficked areas, such as midtown and downtown Manhattan.

Lead poisoning in humans occurs when a person breathes or swallows a substance with lead in it, including dust, paint, water or food, according to WebMD. Lead can damage almost every organ system, which can lead to growth and developmental problems in children and nervous system damage in adults. Children 6 years old or younger are at higher risk.

Symptoms of lead poisoning in children include lower intelligence, below-average body size, lack of energy and appetite, behavioral issues and learning problems. Adults with lead poisoning may experience changes in behavior, personality, sleep patterns and mood. Adults may also exhibit memory loss, weakness, muscle problems or headaches. In severe cases, seizures, paralysis or coma may occur.

Pigeons, which nest on top of buildings, along building facades, beneath bridges and within garage rafters, experience the same exposure to lead concentrations as people do. Pigeons also exhibit symptoms of lead poisoning much like humans do.

Graph courtesy of Rebecca Calisi Rodriguez

Since 2011, citizen scientists have collected pigeons that act “wonky,” says Rodríguez. These birds are admitted to the Wild Bird Fund, where rehabilitators test their blood for lead. Rodríguez compared this data to public records of children’s blood lead levels published by the New York City Department of Health and Mental Hygiene. The neighborhood borders were determined by the New York Department of Health.

Rodríguez found that blood lead level in pigeons matched those found in children living in the same neighborhoods. Further, child blood lead levels were higher in the summer, likely due to more time outside and more exposure to possible contaminants, she said.

These correlations between pigeons and humans may lead to a new way of detecting harmful pollutants for which humans are rarely tested, says Rodríguez. Using these methods, she hopes to develop screening tools that can be widely used, not just to detect toxins, but to determine how they might effect humans.

“Some people refer to pigeons as ‘rats with wings,’ I refer to them as sentinels,” says Rodríguez. “They’re our canary in a coal mine.”